1. Field of the Invention
This invention relates to the polymerization or copolymerization of olefins using a new catalyst. More particularly, it is concerned with a process for preparing polyolefins characterized by polymerizing or copolymerizing .alpha.-olefins in high stereo-regularity using a new catalyst with high-performance carrier.
2. Description of the Prior Art
As a high stereoregular polymerization catalyst for .alpha.-olefins there has heretofore been known a catalyst consisting of a titanium halide and an organoaluminum compound. In the polymerization using such known catalyst system, however, the yield per titanium component is still insufficient though a high stereoregular polymer is obtained, and in recent years to eliminate the need for removal of residual catalyst in the resulting polymer there have been proposed some high-performance catalysts with magnesium halide as carrier (see Japanese Patent Public Disclosure Nos. 16986/73, 16987/73 and 16988/73).